Oh, I know exactly what you mean. I've been out of the loop for some years now, but even at ultimate's offset my competition would fish for those d-tilt openers so transparently ad nauseum (and why wouldn't they?), and I can only imagine the situation now. I'm not here to knock "flowchart" style fighting games, but I play platform fighters to avoid this sort of autopilot paint-by-numbers habdashery, and I refuse to fill my cranium with these pre-canned sequences on principle lul. How melee pulled off its dynamic combo game remains a wonder, that can only be explained by it being a gift from the Greco-Roman pantheon incarnate. Warts and all. Either that or a finely tuned hitstun duration thru extensive playtesting, one of those two. (Though ultimate is still my favorite game to play.)
The d-tilt end lag proposal is interesting, if a bit counterintuitive for laymen and newcomers. I didn't consider the nature of quick unpunishable combo starters being intrinsically OP until you pointed it out. Personally I would like to see something along the lines of buffing DI, to the point where you can mitigate d-tilt's harbinge of devastation, and potentially punish a combo hungry player who didn't notice the abnormal distance. Something to balance "mid" attacks besides slowing them down, it just doesn't feel appropriate to me.
I'd just like to make honorary mention of warlock Punch's lack of end lag. Great design. I mean what business does someone who blocks that instead of evading it, have of punishing anyone. Was full hop or forward roll so insurmountable? I think this is a good rule of thumb for very slow moves, to fashion them into a viable edgeguard tool if nothing else, and they get to keep their full flavor as a big-balls play that only a madman would exercise. It's okay if some specials have extremely fringes cases, as long as they have at least one, in fact I think that's preferable for reasons previously stated.
I see no reason why an exchange across the Z axis should favor either fighter. At least in a world where true combos invalidate the question altogether. Watching someone get juggled around, desperately trying & failing to touch down isn't hype to me, or make me want to take notes, like yeah this up-air is pretty oppressive in this match-up imagine that...in fact it's painful to witness. The damage accrued from the attack that sent them airborne should be punishment enough. Granted this is an ideal. Just as in a perfect world, we can dispense with time-tested movesets across the board and not expect extreme jank and imbalance. (Just look at the aftermath of smash 4/ult DLC additions.)
Aerials are already